Receive a payment from the EU with minimal costs and what should be indicated in these interim transfers/agreements?

Question

Payment systems

Questions to those who have dealt with such translations in practice. In general, I got acquainted with the topic, but incomprehensible points requiring clarification remained.
1. If the customer transfers from the EU, for example, 10k euros, then the best way to work is to open an IP account in euros in the Russian Federation, and the final costs are STS 6% + 13% of the remaining 94% when transferring money to a physical account, total of the amount transfer remains 8178e as a profit (excluding bank commission about 1% of the amount and cost of converting into rubles) ?
2. How does the Agreement look like in such transfers, how are the details of the Customer prescribed? In general, what does this situation look like?
4. What does Russian currency control look like in practice? Has anyone gone through it? What problems might arise?
5. In some of the read topics, there is a suggestion to create a legal entity in Estonia or Scotland. What is the fundamental difference between a direct transfer to an individual entrepreneur's account in the Russian Federation, and a transfer to a legal entity's account in one of these countries and a further transfer to an individual entrepreneur's account in the Russian Federation? And how to draw up such contracts? For example, the Customer pays for services for, for example, software development, and a legal entity in Estonia then pays for IP in the Russian Federation, also for development? If so, how are data transfers and final Acceptance and Transfer Certificates formalized? And how to register all this in the Russian Federation?
6. Is it possible for an individual entrepreneur registered in Russia to open a euro account in the same Estonia and receive money for it, and what does such a scheme look like?
7. Правильно ли я понимаю, что схемы с разного рода платежными системами типа Пионера - подходят только для переводов суммарно не превышающих 100к руб?
В целом какие еще есть подводные камни в этой теме? И возможно ли как-нибудь снизить издержки ниже ~20%? Буду исключительно признателен за дельные советы из собственного опыта.